1 1⁄2 parts St-Germain
2 parts Champagne or dry white wine
2 parts club soda or sparkling water
Stir ingredients in a tall, ice-filled Collins glass, mixing completely. Garnish with a lemon twist. If necessary, substitute sparkling wine, Prosecco or Cava for Champagne. For the dry white wine, Sauvingon Blanc works best.